Such anemometers were used to determine the influence of wind speed and direction on the flight of an aircraft. They helped navigators and pilots to adjust the course, calculate the path to the target, fuel consumption and arrival time. Such devices were especially important during long flights over the sea or in conditions of limited visibility, when visual landmarks were absent. This type of device was installed on several models of Japanese military aircraft of the army and naval aviation of the 1930s and 1940s - fighters, bombers and reconnaissance aircrafts. These machines formed the basis of Japan’s air power during the Second World War.
The special value of the object is given by its origin: the anemometer was transferred to the Museum on October 10, 1974 by a participant of the war with Japan. Thus, the device combines not only a technical, but also a memorial component – as a trophy and personal testimony of the final stage of the Second World War. The device is an airborne aviation instrument in the form of a metal sector with an angle of 45°. It contains a graphic scale, nomograms, correction tables and a movable ruler fixed in the center. With the help of simple mechanical actions the pilot could quickly obtain the necessary navigation data without electronics only thanks to mathematical relations and experience.